1. Field of the Invention
The invention is related to systems for binding a boot on a board and it is related more specifically to the field of snowboarding. It is related to a device enabling the adjustment of the angular position of a binding on a board, especially a snowboard.
2. Description of Background and Relevant Information
Snowboarding is performed with the use of an elongated board on which both feet of a user are immobilized via appropriate retention elements. The positions that are adopted for practicing this sport can be extremely varied. The feet are generally inclined at about several dozen degrees with respect to the median longitudinal axis of the board.
In order to allow an angular adjustment to be made that is adapted to the user's requirements, the most widespread system consists of providing a device that comprises a base plate having an elongate shape equipped with means to receive and affix a boot comprising a central hole in which a disc is housed, the disc being anchored directly in the board by means of several screws that maintain the plate in position on the board by taking support on the edge of the central hole.
U.S. Pat. No. 5,261,689 provides an example of such a binding device that is adapted to receive a flexible snowboarding boot. In this particular case, the disc is equipped with a truncated edge comprising a plurality of radial striations that form a mesh with a plurality of striations, having a complementary shape, of a truncated edge of the central hole of the plate. The bass plate is adjusted by unscrewing the affix screws of the disc and by rotationally displacing the plate by the desired angle. One of the problems encountered in this practice has its origins in gravity, i.e., the disc remains nested and automatically centered in the hole of the base plate. Thus, the meshing of the striations is maintained and this creates a substantial friction force that resists the rotation of the plate during the manual adjustment thereof. Consequently, adjustment is done jerkily and this makes it more difficult to locate the desire angular position.
Furthermore, successive adjustments tend to cause a premature wear and tear of the striations and can result in reduced retention during the rotation of the base plate. Most of the time, the disc must eventually be entirely unscrewed so as to allow the vertical lifting of the disc and enable the rotation of the plate with respect to the disc; this makes the adjustment operation both long and pain staking.
U.S. Pat. No. 5,236,216 is related to a similar device in which the disc comprises a circumferential edge that forms, in conjunction with the edge of a central hole of the base plate, an annular support surface that is circumscribed within a substantially horizontal or parallel plane with respect to the plane of the board. This support surface comprises surface roughnesses or fine serrations so as to adequately secure the base plate by friction. This device is easier to adjust but it cannot ensure an efficient automatic centering of the disc in the hole, nor any substantial rotational resistance due to the planar configuration of the support surface.
The utility design JP-(U)-3001977 is related to a snowboard binding comprising a base plate that is bored with an assembly hole for a disc that is designed so as to be able to get nested in the hole along a smooth support surface having a truncated shape. An independent and offset blocking device equipped with a latch is provided on the side of the base plate in order to latch the base plate with respect to the board. However, this device is not entirely satisfactory either since it is necessary to use an additional disc located between the base plate and the board that comprises housings for positioning the latch. Most importantly, the presence of such a disc creates an over elevation of the boot with respect to the board; this is not very desirable since one needs to retain an adequate perception of sensations vis-a-vis the board.
A binding device known as "Clicker" is available commercially and is distributed by the Shimano company. This device comprises a base plate equipped with a hole for receiving a central disc of a complementary shape that gets nested therein. The disc comprises serrations located along the periphery of the disc edge that get engaged in a plurality of vertical pions located at the periphery of the disc along an edge of the base plate. A dozen or so pions are spaced at a few degrees from one another and distributed along an extensive portion of the perimeter of the edge of the approximately 180.degree. central hole; this does not allow for an easy disengagement of the disc in order to make an angular adjustment.
In addition, the nesting of the trough shaped disc in the hole of the base plate does not allow the disc to slide with respect to the base plate. In order to change the orientation of the plate with respect to the disc, the anchoring screws of the disc must be almost entirely unscrewed so as to be able to raise it enough vertically in order to disengage the serrations and pions forming the rotational stop. The vertical raising of the disc is not practical and generally requires the use of a screw driver that must act as a lever. In addition, this state must be maintained during the entire angular adjustment operation.